Preparation method of pentamethylcyclopentadienyl titanium trichloride

Abstract

The invention relates to a preparation method of pentamethylcyclopentadienyl titanium trichloride, which comprises the following steps: S1, vacuumizing a reactor for replacement, detecting the content of moisture and oxygen in gas in the reactor, and stopping vacuum replacement after the content is qualified; s2, adding titanium tetrachloride and methylbenzene into a reactor, dropwise adding a pentamethyl cyclopentadienyl lithium / potassium solution into the reactor, and reacting to obtain a crude product pentamethyl cyclopentadienyl titanium trichloride; s3, the crude product pentamethyl cyclopentadienyl titanium trichloride obtained in the step S2 is filtered, and a crude product pentamethyl cyclopentadienyl titanium trichloride solid is obtained; and S4, adding the crude product pentamethyl cyclopentadienyl titanium trichloride solid obtained in S3 into a mixed solution of toluene and tetrahydrofuran, carrying out hot filtration, and recrystallizing to obtain a pure product pentamethyl cyclopentadienyl titanium trichloride. The pentamethyl cyclopentadienyl titanium trichloride is synthesized in one step, the method is simple, the reaction efficiency is high, and the synthesis process route is shortened.

Description

Technical Field

[0001] The invention relates to the field of organic catalysts and semiconductor high-purity materials, and in particular to a method for preparing pentamethylcyclopentadienyl titanium trichloride. Background Art

[0002] Pentamethylcyclopentadienyl titanium trichloride is an organic olefin polymerization catalyst and also the raw material of the precursor NxTi. The traditional synthesis method of pentamethylcyclopentadienyl titanium trichloride is to react pentamethylcyclopentadienyl potassium with trimethylchlorosilane to generate pentamethylcyclopentadienyl trimethylsilane, which is then reacted with titanium tetrachloride to generate the product. This process has the disadvantages of long synthesis route and complex post-processing. Summary of the invention

[0003] The invention mainly provides a method for preparing pentamethylcyclopentadienyl titanium trichloride with high product purity and short synthesis route.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] A method for preparing pentamethylcyclopentadienyltitanium trichloride comprises the following steps:

[0006] S1, vacuuming the reactor, detecting the moisture and oxygen content in the gas in the reactor, and stopping the vacuum replacement when the content is qualified;

[0007] S2, adding titanium tetrachloride and toluene into a reactor, and adding pentamethylcyclopentadienyl lithium / potassium solution dropwise into the reactor to react to obtain crude pentamethylcyclopentadienyl titanium trichloride;

[0008] S3, filtering the crude pentamethylcyclopentadienyl titanium trichloride obtained in S2 to obtain a crude pentamethylcyclopentadienyl titanium trichloride solid;

[0009] S4, adding the crude pentamethylcyclopentadienyl titanium trichloride solid obtained in S3 into a mixture of toluene and tetrahydrofuran, filtering it hot and then recrystallizing it to obtain pure pentamethylcyclopentadienyl titanium trichloride.

[0010] Preferably, the water content in the gas in the reactor in S1 is less than 10 ppm, and the oxygen content is less than 50 ppm to be qualified. Preferably, the vacuum replacement method in S1 is: evacuate the reactor to -0.095 MPa, purge with nitrogen to 1 atmosphere, and repeatedly replace.

[0011] Preferably, the pentamethylcyclopentadienyl lithium / potassium solution in S2 is in a completely dissolved state; the reaction temperature is -78°C to 100°C, the pressure is -0.05 to 0.05 MPa, the reaction time is 1 to 24 hours, and the dropwise addition time is 20 minutes to 2 hours.

[0012] Preferably, the mass ratio of titanium tetrachloride, toluene, and pentamethylcyclopentadienyl lithium / potassium in S2 is 0.3-1:2-4:8-23, and the water content of toluene is <5ppm.

[0013] Preferably, the S3 crude pentamethylcyclopentadienyltitanium trichloride is filtered under an inert environment.

[0014] Preferably, the temperature of the heating filtration in S4 is 40-80°C.

[0015] Preferably, the mass ratio of crude pentamethylcyclopentadienyl titanium trichloride solid to toluene and tetrahydrofuran is 1-1.5:2-4:0.1-4.

[0016] Preferably, the purity of the pure pentamethylcyclopentadienyltitanium trichloride reaches above 97%.

[0017] Preferably, the reactor is made of stainless steel.

[0018] The application of the above invention technology has the following beneficial effects:

[0019] The invention adopts pentamethylcyclopentadienyl lithium / potassium and titanium tetrachloride to react in one step to prepare pentamethylcyclopentadienyl titanium trichloride, thereby improving reaction efficiency, shortening the synthesis process route, having high product purity, and having a simple process route and facilitating the construction of production facilities. DETAILED DESCRIPTION

[0020] Example 1

[0021] A method for preparing pentamethylcyclopentadienyl titanium trichloride comprises the following steps:

[0022] Step 1, evacuate the reactor to -0.095MPa, then purge with nitrogen to 1 atmosphere, repeat several times, detect the moisture in the nitrogen purge in the reactor by instrument, and stop vacuum replacement when the moisture content is lower than 10ppm and the oxygen content is lower than 50ppm;

[0023] Step 2, 100 g of titanium tetrachloride and 200 g of dry toluene (water content <5 ppm) are added to a reactor, 800 g of pentamethylcyclopentadienyl lithium / potassium solution is added dropwise to the reactor within 20 min and reacted for 10 h to obtain crude pentamethylcyclopentadienyl titanium trichloride, the reaction temperature is -78 ° C, and the pressure is -0.05 MPa;

[0024] Step 3, filtering the crude pentamethylcyclopentadienyl titanium trichloride obtained in step (2) under an inert environment to obtain a crude pentamethylcyclopentadienyl titanium trichloride solid;

[0025] Step 4, adding the crude pentamethylcyclopentadienyl titanium trichloride obtained in step (3) into a mixed solution of toluene and THF and heating to dissolve, dissolving the product in the solvent, filtering at 80° C. to remove the lithium salt, and then recrystallizing to obtain pure pentamethylcyclopentadienyl titanium trichloride with a purity of 99.1% and a yield of 56%.

[0026] Example 2

[0027] A method for preparing pentamethylcyclopentadienyl titanium trichloride comprises the following steps:

[0028] Step 1, evacuate the reactor to -0.095MPa, then purge with nitrogen to 1 atmosphere, repeat several times, detect the moisture in the nitrogen purge in the reactor by instrument, and stop vacuum replacement when the moisture content is lower than 10ppm and the oxygen content is lower than 50ppm;

[0029] Step 2, 30 g of titanium tetrachloride and 400 g of dry toluene (water content <5 ppm) are added to a reactor, 23000 g of pentamethylcyclopentadienyl lithium / potassium solution is added dropwise to the reactor within 2 h, and the reaction is carried out for 24 h to obtain crude pentamethylcyclopentadienyl titanium trichloride, the reaction temperature is 50 ° C, and the pressure is 0.05 MPa;

[0030] Step 3, filtering the crude pentamethylcyclopentadienyl titanium trichloride obtained in step (2) under an inert environment to obtain a crude pentamethylcyclopentadienyl titanium trichloride solid;

[0031] Step 4, adding the crude pentamethylcyclopentadienyl titanium trichloride obtained in step (3) into a mixed solution of toluene and THF and heating to dissolve, dissolving the product in the solvent, filtering at 40° C. to remove the lithium salt, and then recrystallizing to obtain pure pentamethylcyclopentadienyl titanium trichloride with a purity of 97.2% and a yield of 30%.

[0032] Example 3

[0033] A method for preparing pentamethylcyclopentadienyl titanium trichloride comprises the following steps:

[0034] Step 1, evacuate the reactor to -0.095MPa, then purge with nitrogen to 1 atmosphere, repeat several times, detect the moisture in the nitrogen purge in the reactor by instrument, and stop vacuum replacement when the moisture content is lower than 10ppm and the oxygen content is lower than 50ppm;

[0035] Step 2, 100 g of titanium tetrachloride and 300 g of dry toluene (water content <5 ppm) are added to a reactor, 20,000 g of pentamethylcyclopentadienyl lithium / potassium solution is added dropwise to the reactor within 1 hour for reaction for 1 hour to obtain crude pentamethylcyclopentadienyl titanium trichloride, the reaction temperature is 100° C., and the pressure is -0.02 MPa;

[0036] Step 3, filtering the crude pentamethylcyclopentadienyl titanium trichloride obtained in step (2) under an inert environment to obtain a crude pentamethylcyclopentadienyl titanium trichloride solid;

[0037] Step 4, adding the crude pentamethylcyclopentadienyl titanium trichloride obtained in step (3) into a mixed solution of toluene and THF and heating to dissolve, dissolving the product in the solvent, filtering at 60° C. to remove the lithium salt, and then recrystallizing to obtain pure pentamethylcyclopentadienyl titanium trichloride with a purity of 97.0% and a yield of 41%.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing pentamethylcyclopentadienyl titanium trichloride, characterized in that: The steps include: S1, vacuuming the reactor, detecting the moisture and oxygen content in the gas in the reactor, and stopping the vacuum replacement when the content is qualified; S2, adding titanium tetrachloride and toluene into a reactor, and adding pentamethylcyclopentadienyl lithium / potassium solution dropwise into the reactor to react to obtain crude pentamethylcyclopentadienyl titanium trichloride; S3, filtering the crude pentamethylcyclopentadienyl titanium trichloride obtained in S2 to obtain a crude pentamethylcyclopentadienyl titanium trichloride solid; S4, adding the crude pentamethylcyclopentadienyl titanium trichloride solid obtained in S3 into a mixture of toluene and tetrahydrofuran, filtering it hot and then recrystallizing it to obtain pure pentamethylcyclopentadienyl titanium trichloride.

2. The method for preparing pentamethylcyclopentadienyl titanium trichloride according to claim 1, characterized in that: The moisture content in the gas in the reactor in S1 is less than 10ppm, and the oxygen content must be less than 50ppm to be qualified.

3. A method for preparing pentamethylcyclopentadienyltitanium trichloride according to claim 1, characterized in that: The vacuum replacement method in S1 is: evacuate the reactor to -0.095 MPa, purge with nitrogen to 1 atmosphere, and repeat the replacement.

4. The method for preparing pentamethylcyclopentadienyltitanium trichloride according to claim 1, characterized in that: The state of pentamethylcyclopentadienyl lithium / potassium solution in S2 is a completely dissolved state; the reaction temperature is -78°C to 100°C, the pressure is -0.05 to 0.05MPa, the reaction time is 1 to 24h, and the dropwise addition time is 20min to 2h.

5. The method for preparing pentamethylcyclopentadienyltitanium trichloride according to claim 1, characterized in that: The mass ratio of titanium tetrachloride, toluene, and pentamethylcyclopentadienyl lithium / potassium in S2 is 0.3-1:2-4:8-23, and the water content of toluene is <5ppm.

6. The method for preparing pentamethylcyclopentadienyltitanium trichloride according to claim 1, characterized in that: The crude pentamethylcyclopentadienyltitanium trichloride of S3 was filtered under an inert environment.

7. The method for preparing pentamethylcyclopentadienyltitanium trichloride according to claim 1, characterized in that: The temperature of the heating filtration in S4 is 40 to 80°C.

8. The method for preparing pentamethylcyclopentadienyltitanium trichloride according to claim 1, characterized in that: The mass ratio of the crude pentamethylcyclopentadienyl titanium trichloride solid toluene and tetrahydrofuran is 1-1.5:2-4:0.1-4.

9. The method for preparing pentamethylcyclopentadienyltitanium trichloride according to claim 1, characterized in that: The purity of pure pentamethylcyclopentadienyltitanium trichloride reaches over 97%.

10. A method for preparing pentamethylcyclopentadienyltitanium trichloride according to any one of claims 1 to 9, Features The reactor is made of stainless steel.